Exploring the electrochemical performance of layered BiSe hexagonal platelets as the anode material for lithium-ion batteries.

The escalating need for lithium-ion batteries (LIBs), driven by their expanding range of applications in our daily lives, has led to a surge in interest in metal selenides as potential anode materials. Among them, BiSe stands out as a promising anode material for LIBs due to its unique layered structure. Herein, we explored hexagonally structured layered BiSe platelets synthesized using the solvothermal method. The electrochemical performance of these platelets in LIBs was thoroughly examined, revealing an impressive initial discharge specific capacity of 556 mA h g at a current density of 100 mA g and a coulombic efficiency of 66.5%. Improved cycling stability, rate performance, and discharge voltage profile at various current densities were observed. The plateaus observed during the charge/discharge profile were clearly illustrated by the CV results. The reaction kinetics indicated that both ion diffusion and pseudo-capacitance behavior are crucial for the observed high electrochemical performance. Moreover, the hexagonal BiSe platelets exhibited a high ion-diffusion coefficient of 1.8 × 10 cm s and a charge transfer impedance of 23 Ω post-cycling. Furthermore, the crystal structure, lattice vibrational bonding, and surface morphology of BiSe were explored using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. FTIR spectroscopy was utilized for identifying the functional groups, while X-ray photoelectron spectroscopy (XPS) was used to identify the elemental composition and oxidation states of BiSe.